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Oct. 19, 1954 l. MOLNAR SPACE RESERVATION Filed June 30, 1953 10 Sheets-Sheet 5 IMRE MOLNAR INVENTOR.

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INVENTOR. IM R E MOLNAR Oct. 19,-1954 l. MOLNAR 2,692,378

SPACE RESERVATION Filed June 30, 1953 10 Sheets-Sheet 8 MOI IN ALL LEVELS OF ROD SW.

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IMRE MoLNAR BY @www ATTY.

Patented Oct. 19, 1954 SPACE RESERVATION Imre Molnar, Chicago, Ill., assigner to Automatic Electric Laboratories, Inc., Chicago, Ill., a corporation of Delaware Application June 30, 1953, Serial No. 365,123

14 Claims. l

The invention relates in general to space reservation systems and more particularly to a system for automatically printing space reservation information .bulletins covering a two-week period to indicate the number of available spaces, or seats, on each of a large plurality of scheduled transportation routes, or nights of airplanes, trains, or the like.

The principal object of the invention is to provide animproved space reservation system of the above vmentioned character.

Another object is the provision of means lfor causing code letters, designating differing availabler spaces, or seats, to be printed on partially preprinted bulletins in the proper locations corresponding to the dinerent routes and the various stopping points enroute for such routes.

A feature of the invention relates to the code marking of each space computer indicator, which is individual to each leg, or section, of a route, in accordance with the number of available seats remaining for that particular section of the route. v A further feature relates to the means whereby code markings on the individual space indicators arefsuccessively read, or scanned, in the proper orderto control a common coding control means which transmits over a broadcast teletypewriter circuit to cause teleprinters connected to this broadcast circuit to print corresponding code letters on the partially preprinted bulletins in the proper locations corresponding to the respectiveroute, or night, legs. These preprinted bulletins containing'theroute numbers, and the two letter codes of all stations, or legs, touched by a route. l

Another feature of the invention relates to the periodic scanning of the space indicator circuits and the arrangement whereby the scheduled routes for the current day of the week and the earlier days of a following two-Week period are broadcast at more frequent intervals than are the scheduled routes for the later days of the two-week period. For example, the bulletin space information is broadcast for a fourteen day period and each bulletin contains all routes for this period in which the current, or present, day and the following days available space information is broadcast three times per hour, the second and third days space information twice per hour, the

fourth and nfth days space information once per hour, the sixth and the remaining days space information once every two hours.

Other features of the invention will become apparent upon perusal of the following description taken in conjunction with the accompanying drawings in which the present invention has been applied to a centralized space reservation system for an airplane transportation system.

Figs. 1 and 2 illustrate the detail circuit arrangements of the system.

Fig. 3 diagrammatically illustrates the space reservation system.

Fig. 4 diagrammatically illustrates the multiple connections between the scanning switches and the date switch.

Fig. 5 diagrammatically illustrates the grouping of the space indicators and their connections to the banks of the scanning switches.

Fig. 6 is a chart illustrating the order of access to the scanning switches as determined by the date switch.

Fig. 7 shows the multiple connections in one level of the date switch to the scanning switches.

Fig. 3 shows the multiple connections in all levels of the date switch for one route group for one day of night indicators.

Fig. 9 shows the multiple connections in all levels of the date switch for one route group for another day of night indicators.

Fig. 10 shows in part the printed bulletin with both the preprinted information and the code letters such as E, D, T and O which are printed in the proper places in accordance with this invention to indicate in code the available space in the respective routes, or nights.

General description Briefly, the present invention illustrates a centralized space reservation system in which Teletype printers are controlled to print code letters on a preprinted bulletin sheet in accordance with the available space indicated on the flight space computer indicators.

The preprinted information on the preprinted bulletin sheet comprises the night number and two-letter city abbreviations designating the originating, intermediate and destination stopping points in a night, or route.

There is a space computer indicator, comprising a tens and units switch, for each sector, or leg, of the flight. That is, a night originating in Chicago with stops in Pittsburgh and Philadelphia and terminating in New York would have three indicators. The nrst indicator corresponding to the nrst sector, or leg, for the Chicago to Pittsburgh portion of the night, the second indicator corresponding to the second sector, or leg, for the Pittsburgh to Philadelphia portion of the night, and the third indicator corresponding to the third sector, or leg, for the Philadelphia to New York portion of the flight. These space indicators are operated in the same manner as described in the Molnar application Ser. No. 63,273, led December 30, 1948, now Patent No. 2,647,249, dated July 28, 1953, to count by subtraction the number of reservations for each sector of each flight. Each space computer indicator is wired to give four different battery potential and resistance value markings, dependent upon the number of available space reservations left. rlhese battery pctential markings are periodically picked up by the scanning switches which control relays to cause the Teletype printer to print in code letters the available space in the flight sectors, or legs, on a preprinted bulletin sheet previously printed with the flight number and the city abbreviations designating the sectors of each flight, the available space code letters being printed directly below the city abbreviations representing the flight sectors. Each space indicator has a white lamp to indicate that no seats are available and a green lamp to indicate that one to four seats are available. When neither one of these lamps is illuminated it indicates that five or more seats are available.

There are forty-two RSC scanning switches each having rive wipers and each wiper has access to forty-nine indicators. A 1D0-point switch ROD has fifteen wipers and levels, fourteen of which correspond to a two-week period, there being a wiper and a level for each day of the twoweek period. The motor magnet circuit of each RSC scanning switch is connected and multipled in these fourteen levels of the ROD switch dependent upon its relation to the current day of the week. This multiplying, as will be explained more fully hereinafter, causes the printing of the available spaces for the nights of the current day of the week, as well as the next following day, to appear more frequently than the other days of the two-week period. Each different level of the ROD switch is activated by a manually hand operated switch which is moved by the attendant to select the level corresponding to the current day of the week.

The scanning switches RSC and the code reading switch RDK cause only one space computer indicator to be scanned at a time. Each indicator is so wired that different polarities and different resistance Values are connected for the reading dependent upon the number of seats available. For example, with iive or more seats available the reading is positive polarity and a high resistance value; with two to four seats available the reading is positive polarity and a low resistance value; with one seat available the reading is negative polarity with a high resistance value; and with no seats available the reading is negative polarity with a low resistance value. These readings are translated to cause the bulletins to be printed in the proper places with code letters corresponding to such readings.

Fig. 3 is a schematic one-line diagram of the entire space reservation system including the apparatus of the Molnar patent mentioned above, for selecting, operating and resetting the space computing indicators and including the apparatus of the present invention for scanning, or reading, periodically the available space indications on the indicators in order to cause a Teletype printer to print bulletins in accordance with the space indications on the indicators. As disclosed in the same Molnar application a nder switch connects a reservation clerks position to a local converter circuit which includes a register control switch, register relays, indicator marking relays, a date finder, a circuit control switch, an impulse generator, and an impulse control switch, and selector and connector switches for selecting the desired indicator. The portion of Fig. 3 representing the present invention includes the space computer indicators which are operated under control of the reservation operators, the scanning switches RSC which have access to the indicators by way of a distributing frame DF, the coding relays and switches RDK and RSH, the date switch ROD and hand switch, and the Teletype distributor and receiver-printers controlled thereby to print'l the bulletins periodically.

Referring now to Fig. l, one of the space computer indicators is shown to the extreme left and comprises a units ten-point rotary switch U and a tens ten-point rotary switch T. The rotary switches have an upper set of bank contacts for connecting to a network of four resistances H, L, and H' and L', and a two-section battery BI and B2, common to all indicators, connects a negative or positive potential through a high or low resistance to the scanning lead of this indicator. The neutral lead I 84 of this battery is common to all the indicators and is connected through two poled and a marginal relay to the code reading switch RDK which has access to all the scanning switches RSC. It should be mentioned that another battery indicated by the usual ground and negative battery symbols is used for controlling the other relays and magnets. The lower set of bank contacts of switches U and T are provided to control a White lamp W and a green lamp G when only a few available spaces remain in the sector of night corresponding to this indicator. The switch U has off normal contacts ||3 which are closed in only the rst position, off normal contacts IIll which are closed in positions two to ten, inclusive, off normal contacts |I5 which are open in positions two to ten, and a double wound motor magnet I I0 for stepping the wipers I I I and I I2 on deenergization. The switch T has off normal contacts |23 which are closed in positions two to ten, contacts |24 which are open in positions two to ten and a motor magnet |20 for stepping wipers IZI and |22 on deenergization. The motor magnets ||0 and |20 are controlled by irnpulses transmitted over conductor I I6 which terminates in the banks of both the regular connector and reset connector shown and described in the Molnar patent mentioned above. There is one space computer indicator for each night sector, or leg, of each flight.

The scanning lead I2t` of each indicator terminates in a distributing frame DF where jumpers are run to connect such scanning leads to the proper bank contacts of the rotary type scanning switches RSC. In the present system there are forty-two scanning switches, one (RSCI) of which is shown while the remaining are indicated in the upper portion of this ligure. Each scanning switch comprises five fifty-point bank contact sets and associated wipers, a motor magnet, such as magnet |30 for stepping the wipers on deenergization, and off-normal contacts |37, I 38 and |39 shown in normal position. The wipers of each scanning switch normally rest in engagement with their fftieth bank contacts which are left dead, or disconnected. The wipers |3| of all scanning switches are multipled to common conductor |63 which terminates in the first bank contact of the code reading switch RDK. In a similar manner the second to the fth wipers of the Scanning switches are multipled and connected to the bank contacts of switch RDK, as shown.

The common code reading switch RDK is a tenpoint Irotary switch which steps its wipers upon deenergization of its motor magnet |40 to conneet with successive wipers of the `scanning switch in use and to control the Teletype distributor diagrammatically shown in the upper portion of Figs. 1 and 2. The Teletype distributor is well known and is used to control a Teleprinter in a well known manner. A space relay SP and code relays PR, NR and RR are shown for transmitting space and code impulses to the Teletype distributor to control the Teleprinterf In Fig. 2 line feed LS, carriage return CR, clutch CL, and tabulator TAB relays are shown for controlling the Teletype distributor in a well known manner.

In Fig. 2 the rotary switch RSH is a ten-point rotary switch having a motor magnet 24|)` for stepping wiper 244 on decnergization and off-normal contacts 242 which close when the switch steps off normal. Two thermo-relays BI and BM have bi-metal contacts 209 and 244 which close after a predetermined energization of these relays. TA and TB indicate the well-known dashpot type of relays which close their contacts 2&7 and 2I8 after a predetermined energization to ground the trouble alarm lead. A constantly ro tating interrupter I controls the pulsing relay BP. A start key STK is manually operated by the operator to start the apparatus.

A date switch ROD is shown to the right of Fig. 2 having fteen levels of bank contacts comprising one hundred bank contacts each and lifteen wipers. Fourteen of these wipers represent a two-week period with one level for each day of the two-week period. The fteenth level is a space control level and the motor magnet 250 steps these wipers upon deenergization. It will be understood that smaller capacity switches with transfer control therebetween could be used instead of the large one hundred point capacity switches and this large capacity switch is used in this instance for simplicity. A manually operated hand switch 29| is shown to the extreme right of Fig. 2 and is operated by the operator to engage the wiper of the date ROD switch oorresponding to the current day of the two-week period. That is, the hand switch 29| is manually moved to select, or activate, only one of the fourteen levels. The bank contacts of the fourteen levels of the date switch ROD are connected to the motor magnets of the scanning switches and are multipled in a manner indicated in Figs. 6, '7, 8 and 9.

In Fig. 4 the motor magnets of all the scanning switches RSC are shown with a part of their multiple connections to the bank contacts of three of the fourteen levels of switch ROD, namely level I (Monday MOI), level 2 (Tuesday TUI) and level I4 (Sunday SUZ).

Fig. 5 shows the indicators for flights IUI, |03, |05 and |09. Flight I III originates in Chicago and ends in Omaha, the rst sector, or leg, of this flight is from Chicago to Moline, the second sector is from Moline to Des Moines, and the last sector is from Des Moines to Omaha. Flight |03 is from Cleveland to San Francisco and includes eleven sectors, or legs, the rst leg being from Cleveland to Toledo and the last leg being from Sacramento to San Francisco. Flight |05 is from St. Louis to Seattle comprising four sectors, or legs, and flight |09 is from Denver to San Francisco comprising only three legs, or sectors. Each sector, or leg, of each flight includes an indicator, such as shown by the switches U and 'I' in Fig. 1, which are cross connected through the distributing frame DF to the bank contacts of the scanning switches RSC. As will be noted the first sector of flight IOI is connected to the first bank contact accessible to the A wiper I3I, the second sector is connected to the first bank contacts accessible to the B wiper |32, and the third sector is connected to the first bank contact accessible to the C wiper |33. Since iiight IIJI comprises only three sectors the first bank contacts accessible to the DI34 and EI35 wipers are connected to ground. In a similar manner the first five sectors of flight ID3 are connected to the second bank contacts accessible to wipers A, B, C, D, and E, the next rive sectors are connected to the third bank contacts, and the last sector is connected to the fourth bank contact accessible to wiper A; the remaining fourth bank contacts being connected to ground. The other flight sectors are connected in a similar manner.

Fig. 6 is a chart showing the multiple connections within each level and between the fourteen levels of the ROD switch. The upper horizontal row numbered I to I4, inclusive, designates the fourteen levels of switch ROD, the rst vertical column numbered i to 3?., inclusive, designates the number of readings in one transmission cycle, and the second vertical column, beginning with MOI, indicates the multiplying within the level; that is, MOI appears opposite the 1st, 6th, 11th, 17th, 22nd and 27th readings indicating six multiple connections in level I. MOI is likewise multipled between the various levels in accordance with the appearances of MOI in these respective levels. In` a similar manner the remaining designations, such as TUI, WEI, etc., are multipled. It should possibly be stated that MOI stands for the current day of the two-week period which in this case is Monday, TUI for the next day, or Tuesday, WEI for Wednesday, and that M02 stands for the following Monday, or a week from Monday MOI.

Fig. 7 shows all the bank contacts of the first level, or level I, of the ROD date switch, their multiple connections, and connections to the motor magnets of all the scanning switches RSC. For example, contacts I, IS, 32, 5|, 65 and 82 are multipled to conductor ItlI connected to motor magnet |30 of` scanning switch RSC I and is also muitipled to contacts in other levels. Contacts 2, il, 33, 52, El S3 are multipled together and to the contacts in other levels and to the motor magnet of the second scanning switch RCSZ.

Fig. 3 shows all of the multipled connections in all fourteen levels of the date switch ROD for the current day of the week, or Monday MOI. For example, the conductor ISI connected. to the motor magnet |30 of scanning switch RSC is 'multipled to the lst, 16th, 32nd, 51st, 65th and 82nd bank contacts in level I (MOI), to the 94th bank contact in level 2 (TUI), to one contact in levels 3 to 9, inclusive, to two contacts in levels I0 and II, to four contacts in levels I2 and I3, and to six contacts in level I4. The conductors connected to the motor magnets of scanning switches R502 and RSC3 are similarly connected.

Fig. 9 shows all the multiple connections in all fourteen levels of the date switch ROD for Tuesday TUI and designates which contacts are connected to the motor magnets of the scanning switches RSC'I, RSC8 and RSC. The other designations WEI, etc., follow a pattern similar to that shown for MOI and TUI in Figs. 8 and 9.

Fig. 10 shows a completely printed bulletin printed by the teletypewriter on a partially preprinted sheet. The first horizontal row designates the initial starting point of a flight, the sectors, or stopping points or legs, and the destination of a given flight and the second horizontal row designates the numerical flight number and a code letter, such as E, D, T, or O, directly below each sector for designating in code the space available on each sector. For example, the letters CGMODMOH and flight number 101 in the first two horizontal rows designate that flight #101 from Chicago to Omaha comprises three sectors, or legs, the first leg being from Chicago to Moline, the second leg from Moline to Des Moines, and the third leg from Des Moines to Omaha. The letters in the rst horizontal row and the flight numbers in the second horizontal row are preprinted. The printing of the code space letters, such as E and D in the second horizontal row are printed by the teletprinter under control of the apparatus shown in Figs. 1 and 2. The letter E designates that more than five seats are available for the corresponding leg of the flight, the letter D designates that there are from two to ve seats available, the letter T designates that one seat is available, while the letter O designates no available seats. The first and second horizontal rows also show flights 103 and 105 with flight 103 being from Cleveland to San Francisco and having eleven sectors, or legs, while flight 105 from St. Louis to Seattle has four sectors, or legs. It will be noted that the preprinted sheet is divided into ve vertical columns and if a given flight comprises more than live sectors, or legs, only the iirst five legs are in one column while the next ve legs are in the next right hand column, etc. The reason for this spacing on the bulletin is due to the apparatus used for taking the readings on the indicators.

Before proceeding with the detail description of the present invention, it will be noted that the space computer indicators, one of which is shown in Fig. 1, are selected and then operated by impulses in the same manner as described in the Molnar patent mentioned above. That is, the desired set of flve indicators is selected by the flight connector and impulses are transmitted thereto to set these indicators in accordance with the desired flight reservations under control of the reservation operators. The space computer indicator shown in Fig. 1 and the other selected indicators are operated by impulses transmitted over conductors, such as conductor IIS, which are connected to the bank contacts of the flight connectors and the reset connectors.

The reset apparatus of the previously mentioned Molnar application is utilized by the supervisory operator to reset the indicators of a flight after the departure of such flight. That is, the supervisor operator controls the reset converter, the reset selector and the reset connector to select the indicators of this departed flight in order to change the setting of the indicators to conform to the seating capacity, or available space, of the same flight for a following day, in this instance for a day two weeks from the departed flight. The reset apparatus rst causes all of the indicators of this flight to be restored to normal and then causes the indicators to be set in accordance with the seating capacity, or available space, of this ilight. The respective indicators of this flight are now set in accordance with any previous reservations, each reservation subtracting one space from the remaining available space.

Each space indicator, or space computer indicator of the present invention, has a maximum capacity of eighty-nine spaces and if any iiight has a capacity less than eighty-nine it is necessary to subtract a number of spaces so that the remaining spaces correspond to the available spaces, or seats, on the flight. For example, if a llight has a capacity of only twenty-five spaces then the reset converter steps the indicator from normal to its sixty-fourth position to indicate twenty-live available spaces after which each reservation is subtracted from the remaining available spaces.

Reservation operation of space indicators The space computer indicator shown in Fig. 1 is shown as set in its 64th position; that is, it is in a position which indicates that there are twenty-five available seats in the plane for the leg of the journey which this indicator represents. The wipers of the tens switch T are in their eighth position while the wipers of the units switch U are in their fifth position. When the units switch wipers have made twenty-live steps and the tens switch wipers have made two steps from this position to their tenth positions in response to twenty-five reservations, the seating capacity of the plane for this leg of the journey is fully reserved. Battery impulses are transmitted over conductor IIB to the motor magnets I i0 and |20 from either the connector or reset connector in the manner described in the previously mentioned Molnar application. For example, with the indicator in the position shown in Fig. 1 and if the reservation clerk desires to make a single reservation, an impulse is trans,- mitted as follows: battery, conductor IIB, lefthand winding of magnet I I0, off-normal contacts I4 which are closed in position two to ten, righthand winding of magnet ||0 to ground. Motor magnet |||J is energized over this circuit and on termination of the reservation impulse the magnet deenergizes to step its wipers and ||2 into engagement with their sixth bank contacts. Since the oil-normal contacts I I3 are closed only in the first position of switch U the circuit to the motor magnet |20 of the tens switch T is not closed at this time. However, when enough reservation impulses have been transmitted over conductor ||6 to position the wipers of the units switch U in their first position in engagement with their first bank contacts the olf-normal contacts I3 are closed with the result that the next transmitted reservation impulse over conductor I I6 now operates both motor magnets II!) and |20. Magnet I I0 is now operated over conductor l I6, left-hand winding of magnet I l0, oli-normal contacts ||5 which are closed in only the first position of the units switch U, off-normal contacts |23 which are closed in positions two to ten of the tens switch T, and through the righthand winding of magnet I l0 to ground. Magnet |20 is operated by way of conductor IIS, ofinormal contacts I |3 which are closed in only the first position of the unit switch U, and the winding of motor magnet |20 to battery. On termination of this impulse both magnets ||0 and |20 deenergize. Magnet Il steps its wipers to their second positions in engagement with their second bank contacts, opens olif-normal contacts I I3 and ||5 and closes oil-normal contacts H4. Magnet |20 steps its wipers |2| and |22 from its eighth bank contacts to engage its ninth bank contacts.

Further impulses continue to step the units switch U as described until it again reaches its rst position whereupon a following impulse will again operate both motor magnets to cause both switches to step their wipers. Reservation impulses are transmitted to this indicator until all seats have been reserved.

It should be mentioned at this time that each space computer indicator is provided with two lamps, a green lamp G to indicate to the reservation clerk that one to four seats are available, a white lamp W to indicate that no seats are available as all reservations are taken, and when neither lamp is lighted it indicates to the reservation clerk that five or more seats are available for this sector of the flight. When more than ve seats are available the wipers H2 and |22 do not close any circuits for either lamp. When there are from one to four remaining seats in this flight sector wiper i 2 will be in engagement with one of vthe four multipled bank contacts, such as the sixth, seventh, eighth and ninth bank contacts and wiper |22 will be in engagement with its ninth bank Contact. A circuit is now completed for lighting the green lamp G as follows: ground wiper |22 and its tenth bank contact, wiper I l2 in engagement with one of the four multipled bank contacts, and green lamp G to battery. The illumination of the green lamp CZr in this indicator indicates to the reservation clerk that from one to four seats are available. When all the seats in this flight sector are reserved both wipers ||2 and |22 are in engagement with their tenth bank contacts and the white lamp W is lighted over the following circuit: ground, wiper |22, tenth bank contact of the tens switch T, wiper ||2 of the units switch U, tenth bank contact, and white lamp W to battery. The reservation clerk can, by observing the illuminated, or non-illuminated, condition of each indicator, determine if any seats are available for reservations in any desired flight sector.

Reset operation of space indicators 'Ihe space computer indicators are reset after the plane has departed on its scheduled flight in the manner described in the previously mentioned Molnar application. Briefly, the supervisory operator controls the reset converter, the reset selector and the reset connector to select the indicators of this departed night. The reset apparatus then transmits a train of impulses over conductor H5 to operate the units and tens switches U and T until both the wipers of these switches are set in their first positions at which time the oi-normal springs H3, ||5 and |24 are closed. When the ofi-normal springs are closed the resistance in the impulsing circuit is reduced to enable a cut-orf relay in the reset apparatus to 4be operated to stop further transmission of the resetting impulses. In explanation of this cut-off arrangement it will be observed that due to these oit-normal contacts certain windings of the motor magnets ||0 and |20 are included in the resetting mpulsing circuit. For example, in positions two to ten of the units and tens switches U and T, the resetting impulsing circuit over conductor H6 includes only both windings of magnet ||0 as off-normal contacts I3 and ||5 are open and oir-normal contacts I4 are closed. The right-hand winding of magnet I!) is of high resistance as compared to the left-hand winding. The total resistance in this circuit is too high to permit the operation of the cut-oir relay in the reset apparatus. When the units switch U is in its nrst position and the tens switch T is in its second to tenth positions the high resistance winding of magnet |29 is connected over contacts I I3 in parallel with a series circuit including both windings of magnet HG which includes oir-normal contacts H5 and |23. Due to the high resistance or the right-hand winding of magnet I0 and the high resistance winding o1 magnet |20 the total resistance in the resetting impulse circuit is too high to operate the cut-ofi relay in the reset apparatus. Therefore the reset apparatus continues to transmit impulses until both the units and tens switches simultaneously reach their` .First positions where the resistance in the resetting impulse circuit is lowered enough to cause the reset cut-oilc relay to operate. This circuit, with both switches in their first positions, includes only the low resistance left-hand winding of magnet iii! and the winding of magnet |29 in parallel over ofi-normal contacts ||5 and |24 to ground and ofi-normal contacts |3, winding of magnet |22] to ground. Due to the substitution of ground at contacts |24 for the high resistance right-hand winding of magnet the marginal cut-off relay in the reset apparatus operates to open the reset impulsing circuit. The indicator units and tens switches U and T have now been set to their normal positions, that is both switches in their rst positions.

The supervisory operator now transmits a predetermined number of impulses over conductor i6 in order to set these indicators in accordance with the seating capacity of the plane for this flight sector. In case this particular flight has a capacity of twenty-five seats then the indicator switches receive enough impulses to set the wipers of these switches in positions so that twenty-live reservation impulses will set the Wipers of both the units and tens indicator switches in engagement with their tenth bank contacts. The indicator switches U and T in Fig. 1 are shown in a position from which twenty-five reservations can be made.

After the supervisory operator has set the indicators to correspond to the seating capacity of the plane she then transmits a pulse over conductor ll for each registration previously made for this flight, such previous registrations having been made more than two weeks ahead of such scheduled flight.

Detail circuit operations Having described how the space computer indicators are operated, a detail description of the circuit operations for controlling Teletype printers to print code letters on the partially preprinted bulletins will now be given.

Assuming that the partially preprinted bulletins have been properly placed in the Teletype printers and when it is desired to print these bulletins, the bulletin clerk, or operator, will move the hand switch 2Q| to engage one of its terminals corresponding to the current day of the week. For example, if on the first Monday of a two-week period, the operator desires to print bulletins the hand switch 23| (Fig. 2) is moved to engage bank contact MO| after which she will operate the start key STK.

Start key STK at contacts 242 grounds the motor start lead to start the Teletype distributor and printer motors and at contacts 243 closes a circuit for energizing the thermo relay BM over contacts 234. After an interval relay BM closes contacts 244 to energize start relay ST from ground at contacts 243. f Start relay ST at contacts 23| disconnects ground from conductor |83 to open the restoring circuits of scanning switches RSC; at contacts 232 applies another ground to the distributor motor start lead; at contacts 233 completes a locking circuit for itself; at contacts 234 opens the circuit to the thermo relay BM which may now release; at contacts 235 completes a circuit for relay BP in series with interrupter I; at contacts 231 removes ground from Conductor |95 to open the selfrestoring circuit of switch RDK; at contacts 24| opens a point in the self-restoring circuit of switch RSH; at contacts 239 opens a point in the self-restoring circuit of switch ROD; and at contacts 238 closes a circuit for energizing thermo relay BI over contacts ZIB and for energizing the lower winding of pick-up relay PU over conductors |99 and |98 and contact |54. Thermo relay BI will only operate and close its contacts 209 to ground the trouble alarm relay in case the pick-up relay PU fails to operate and open its energizing circuit at contacts EIS. If for any reason the pulse relay BP operates and closes contacts 223 before the pick-up relay PU operates then the pick-up relay PU will not operate until the pulse relay BP restores because relay PU is differential and will not operate when both its windings are energized; the upper winding of relay PU being energized from ground over contacts 236, 223, 2I4 and |53 when relay BP operates before relay PU. Initial operation of relay BP before PU is without effect if such action occurs. This arrangement is provided so that a full impulse will be transmitted by relay BP for the coding operation only after the pick-up relay PU is operated.

Pick-up relay PU operates over the circuit traced through its lower winding. Relay PU at contacts 2|I prepares a code pulsing circuit to relays PR, NR and RR; at contacts 2|2 prepares a circuit to the delay relay DA; at contacts 2|3 prepares a circuit to the clutch relay CL and relay SM; at contacts 2|4 opens the circuit to its upper winding; at contacts 2|0 opens the circuit to thermo relay BI before it operates and closes contacts 209; and at contacts 2|5 closes a circuit for both trouble alarm time dash pot relays TA and TB. These dash pot relays are of the solenoid magnet type and only operate their associated contacts 2I1 or 2 I8 after a predetermined time has elapsed.

When pulse relay BP is operated for a full pulse over interrupter I, contacts 223 close a circuit for energizing clutch relay CL and relay SM in multiple from ground at contacts 236, 223, 2 I3, 206 to relay CL and battery and through the lower winding of relay SM to battery. Clutch relay CL operates before relay SM because relay SM has its upper winding shortcircuited over contacts 205 of relay CL. Clutch relay CL operates contacts 220 to open the circuit to the clutch magnet of the distributor to permit one cycle operation of the distributor in the well-known manner. Clutch relay CL at contacts 205 opens the short-circuit around the upper winding of relay SM to allow this relay to operate and open the circuit to relay CL so that the latter relay will release and reclose the distributor clutch magnet thereby permitting only one cycle operation of the distributor. At contacts 222 relay BP closes a circuit for operating the carriage return relay CR and for energizing delay relay DA. The circuit for operating the carriage return relay CR may be traced as follows: ground, contacts 222 and 2| 2, conductor |92, wiper |42 and last bank contact of switch RDK, conductor |15, Wiper 244 and last bank Contact of switch RSH, conductor |89, contacts |1I, conductor |81, winding of relay CR to battery. A branch of this circuit extends by way of contacts 203 and conductor |9| to delay relay DA but this relay due to its copper slug, as indicated by its upper black end, is slow to operate with the result that relay CR operates before relay DA and at contacts 203 opens the energizing circuit to relay DA before it can fully operate.

At contacts 2|0 carriage return relay CR closes the circuit for operating the carriage return of the distributor in a well-known manner to properly position the teleprinter carriage for printing in the first vertical column. At contacts 204 relay CR closes a circuit for operating relay VB. Relay VB at contacts 20| closes a shortcircuit around the lower winding of relay VA as well as a locking circuit for maintaining relay VB operated after relay CR releases.

Pulse relay BP restores when interrupter I terminates the impulse thereto and at contacts 222 terminates the pulse to relay CR which restores to open the carriage return circuit at contacts 2| 0. Relay CR at contacts 203 again prepares the circuit to the delay relay DA and at contacts 204 opens the original energizing circuit of relay VB and also removes the short circuit from around the lower winding of relay VA. Relay VA is now operated and relay VB is maintained operated over ground contacts 202, 20|, lower winding of relay VA and winding of relay VB to battery. Relay VA at contacts |1I opens the circuit to relay CR; at contacts |12 prepares a circuit for the line feed relay LS and step relay SC; and at contacts I'I3 prepares a locking circuit through its upper winding which is eifective when the pulse relay BP is subsequently operated.

When pulse relay BP is again operated by the interrupter I relays CL and SM again operate over contacts 223 to cause the operation of the distributor clutch magnet as previously described. Line feed relay LS and step relay SC are now operated as follows: ground, contacts 222, 2I2, conductor |92, wiper |42 and tenth bank contact, conductor |15, wiper 244 and tenth bank contact, conductor |89, contacts |12, conductor |88, and through the windings of line feed relay LS and step relay SC to battery. Since relay CR is not operated during this pulse, delay relay DA is operated over contacts 203 after a slight delay. At contacts |6| delay relay DA prepares a point in the coding circuit which at this time is ineffective since the wipers of the switches RDK and RSCI are in their normal positions as shown in Fig. l. At contacts |62 relay DA extends the ground pulse through the winding of the motor magnet |40 to energize the same to position its stepping pawl preparatory to stepping the wipers of the RDK switch. Relay SC also at contacts 201 energizes the motor magnet 240 to prepare to step the wipers of the RSH switch and to short circuit time alarm dash pot relay TA to cause its release before it is fully operated. At contacts 208 step relay SC completes a circuit for energizing motor magnet |30 of scanning switch RSCI as follows: ground, contacts 208, conductor 292, hand switch 29|, bank Contact MOI, wiper I of the date switch ROD and rst bank contact, conductor |8|, and Winding of motor magnet |30 to battery. Magnet |30 energizes contacts 200 to send a line feed pulse to the' distributor to perform a line feed operation in the well-known manner to position the bulletin so that the teleprinter can print theiirst code letter E in the second horizontal line to the right of night numeral in the rst ve vertical columns shown in Fig. 10. At contacts 202 relay L3 opens the circuit of relays VA and VB whereupon relay VB restores while relay VA is maintained operated over its upper winding for the duration ofthe ground pulse over contact 222.

When the interrupter I restores pulse relay BP, relays SM, VA, LS, SC and DA and motor magnet |40 restore. When relay SC restores the circuits to motor magnets 240 and |30 are opened and these magnets restore. The restoration of magnet |40 steps wipers |4I, |42 and |43 of switch RDK into engagement with their first bank contacts. The restoration of magnet 240 steps wiper 244 of switch RSI-I into engagement with its first bank contact and the restoration of magnet |30 steps the wipers ISI-|35, inclusive, into engagement with their rst bank contacts. O-normal contacts 242 of switch RSH now closes to prepare a self-restoring circuit for switch RSI-I. Offnormal contacts |3'| of scanning switch RSCI now closes to prepare a self-restoring circuit for this switch and at oil-normal contacts |38 completes a circuit from ground over conductor |50 for operating slow to release relay KP. Relay KP at contacts |55 prepares a circuit for operating motor magnet 250 of the date switch ROD when the first scanning switch has completed one revolution back to its normal position. The switches are'now in position to take the code reading of the first space computer indicator connected to the first bank contact accessible to wiper |3| of the first scanning switch RSCI.

When pulse relay BP is again operated relays CL and SM again operate over contacts 223 to cause the distributor to take one revolution; relay DA and motor magnet |40 are again energized over contacts 2|2 and relay DA at contacts IGI completes the code reading circuit for the rst indicator over the following circuit: from positive pole oi battery BI, low resistance L, high resistance H, multipled bank contacts of the tens switch T and its wiper |2|, conductor |26, through the distributing frame DF over jumper |21, conductor |28, rst bank contact of scanning switch RSCI and its wiper |31, conductor 163, first bank contact of switch RDK and its wiper Illi, winding of positive relay PR which is shorted by rectier RI blocking fiow of current in this direction, through the rectifier R2 which is poled in the opposite direction thereby shorting negative relay NR when current flows in this direction, winding of relay RR, contacts IGI, conductor |86, contacts 2|| and 22| to the neutral conductor |84 which is connected to the midpoint of batteries BI and B2. Positive relay PR alone energizes over the circuit because relay RR is marginal and will not operate when either the high resistance E or H' is connected in series therewith.- Due to rectifier RI, positive relay PR will only operate when positive current from battery Bl is connected over wiper |4| and rectifier R2 -will cause negative relay NR to operate only when negative current from battery B2 is connected to wiper |4|. It should be here mentioned that relay SK is connected to a different battery other than batteries BI and B2 and will not operate unless ground is connected tol wiper |4|.

Positive relay PR alone is energized over the above traced coding circuit and this relay at oontacts |70 completes a circuit in the distributorV for causing the teleprinters in this revolution to print the code letter E on the preprinted bulletin sheets shown in Fig. 10 to the right of the iiight number |0| and directly below the letters MO in the first horizontal line comprising letters CGMODMOH.

When the flrst coding pulse is terminated by pulse relay BP restoring, relays SM, DA and PR and magnet |40 restore. Magnet |40 in restoring steps the wipers |4I, |42 and |43 of reading switch RDK into engagement with their second bank contacts where wiper |42 prepares a circuit for operating space relay SP. Wiper |4| engages a dead contact so that no coding circuit is completed for relays PR, NR and RR on the next operation of pulse relay BP.

When pulse relay BP again operates relays CL, SM and DA and magnet |40 energize as previously described. In the even numbered positions of wiper |42 a circuit iscompleted for operating space relay SP as follows: Ground contacts 222, 232, conductor |92, wiper |42 in its second position and winding of space relay SP to battery. Relays CL and SM again cause the teleprinter to make one revolution while space relay SP at contacts |06 completes a circuit to cause the printer to take one horizontal step preparatory to printing the next code letter on the bulletin under the letters DM of the first horizontal line in Fig. 10.

When the spacing pulse is terminated by relay BP, relays SM and DA and magnet |40 restore and the wipers of the reading switch are stepped into engagement with their third bank contacts preparatory to code reading the second space computer indicator which is connected to the rst bank contact accessible to wiper |32 of the first scanning switch RSCI.

Assuming that ive or more seats are available in the next sector of flight |0|, the second indicator will be in a position similar to that shown for the first indicator shown in Fig. l, and when the pulse relay BP is operated for the second coding pulse, similar circuit operations as previously described take place to cause the teleprinter to print the code letter E directly below the letters DM of the first horizontal line in the bulletins as shown in Fig. 10. That is, relay PR is operated from positive battery Bl over the high resistance H, wiper |4| in engagement with its third bank contact and the neutral return lead to battery BI. The termination of the second coding pulse by relay BP causes the wipers of the reading switch RDK to advance to their fourth bank contacts where another spacingl impulse is transmitted to the teleprinter as previously described by relays BP and SP; after which the wipers of switch RDK are advanced to engage their fifth bank contacts. When relay BP operates again the third space computer indicator is read over wiper |4|, conductor |65, and wiper |33 to selectively operate the coding relays PR, NR or RR in accordance with the setting of the tens and units wipers of the third indicator.

Assuming that only from two to four seats are available in night |0| in the third sector of the flight from Des Moines` (DM) to Omaha (Ol-I) then the tens wiper of the third indicator corresponding to wiper |2| would be in engagement with its tenth bank contact and the units wiper of the third indicator corresponding to wiper would be in engagement with the three multipled sixth, seventh and eighth bank contacts. With the wipers of the third indicator in the positions just stated the high resistance H is bypassed and the coding circuit includes the positive pole of battery BI, low resistance L, the three multipled unit, bank contacts and wiper of the units switch, the tenth bank contact and wiper of the tens switch, distributing frame DF and jumper, the rst bank contact engaged by wiper |33, conductor |65, fifth bank contact and wiper |4|, relay PR, rectifier R2, marginal relay RR, contacts |6|, 2|| and 22| to the neutral battery lead |84 to battery B Since the high resistance H is by-passed in this circuit both relays PR and RR operate. The simultaneous operation of these two relays transmits over contacts |10 and |90 a code combination to cause the teleprinter to print the code letter D directly below the letters OH (Omaha) in the rst horizontal line shown in Fig. l0. The code letter D indicates that from two to four seats are available in ilight |0| from Des Moines to Omaha.

In case only one seat is available in flight |0| in the third sector of this flight, then the tens wiper of the third indicator corresponding to wiper |2| would be in engagement with its tenth bank conta-ct and the units wiper of this third indicator corresponding to wiper would be in engagement with its ninth` bank contact. Under these conditions the coding circuit may be traced as follows: negative pole of battery B2, low resistance L', high resistance H', ninth bank contact and units wiper of the third indicator, tenth bank contact and tens wiper of the third indicator, terminals and jumper of distributing frame DF, rst bank contact engaged by wiper |33, conductor |65, iifth bank contact and wiper |4|, rectier RI, winding of relay NR, relay RR, contacts |E|, 2||, 2|2, neutral lead |84 to the other pole of battery B2. Rectifier Rl passes current ow in this direction while rectier R2 blocks such flow with the result that relay NR alone is energized in this circuit because marginal relay RR will not operate in series with high resistance H. Negative: relay NR at contacts |80 closes a circuit to the distributor to cause the teleprinter to print the code letter 'I' indicating only one available seat in flight |0| from Des Moines to Omaha.

In case no seats are available in flight |0| in the third sector, or leg, of this flight, then the tens wiper of the third indicator corresponding to wiper |2| would be in engagement with its tenth bank contact and the units wiper of the third indicator corresponding to wiper I I would be in engagement with its tenth bank contact. Under these conditions the coding circuit bypasses the high resistance H and the coding circuit includes only the low resistance L with the result that both relays NR and RR are operated over the coding circuit. Relays NR and RR at contacts |80 and |90 transmit a code combina.- tion to the distributor to cause the teleprinter to print the letter O indicating no available seats in flight |0| from Des Moines to Omaha.

After transmission of the third coding impulse and the third space pulse, the wipers of the code reading switch have advanced, as previously described, to engage their seventh bank contacts. Since ight |0| from Chicago to Omaha comprises only three sectors, or legs, Chicago to Moline, Moline to Des Moines, and Des Moines to Omaha, only three space computer indicators are assigned to this flight. Under these conditions the first bank contacts accessible to wipers |34 and |35 are jumpered through the distributing frame DF to ground. Therefore, when wiper |4| engages its seventh bank contact a circuit is completed for operating skip relay SK as follows: ground, terminals and jumper of the distributing frame DF, rst bank contact and wiper |34, conductor |66, seventh bank contact and wiper |4|, lower winding of skip relay SK to exchange battery. At contacts |5| and |52 relay SK closes a locking circuit for itself as follows: grounded contacts |52, multipled bank contacts and wiper |43, contacts |5| and the upper winding of relay SK to battery. A branch of this` circuit extends through stepping magnet |40 to battery for energizing the same. At contacts |53 and |54 relay SK opens the circuit of the pick-up relay PU which restores. Magnet |40, upon energizing, at contacts |44 interrupts its own circuit and deenergizes to step the Wipers of switch RDK to the next set of bank contacts. Relay SK is held operated and magnet |40 continues to interrupt its own circuit until the wipers of switch RDK are stepped to their tenth positions at which time the magnet self-interrupting circuit and the locking circuit of relay SK are opened. Relay SK restores and at contacts |53 and |54 restores the circuits for relay PU to reoperate relay PU over its lower winding as pre- Viously described.

The next full operation of pulse relay PB, following the reoperation of pick-up relay PU, again operates relays CL and SM at contacts 223, again operates delay relay DA and magnet |40 at contacts 222, and closes a circuit for operating tabulator relay TAB and stepping relay SC as follows: grounded contacts 222, 2|2, conductor |92, wiper |42 in engagement with its tenth bank contact, conductor |15, wiper 244 in engagement with its rst bank contact, and windings of relays TAB and SC to battery. At contacts 230 tabulator relay TAB sends a tabulator code through the distributor to cause the teleprinter to make a tabulator operation in the well-known man- I ner to cause the teleprinter to position the teleprinter carriage so that the next code letter will now be printed to the right of flight number |03 and directly below the code letters TL shown in the rst horizontal line and in the second vertical column.

Flight #|03 from Cleveland to San Francisco comprises eleven sectors, or legs, indicated by the pairs of coded letters, such as CV TL CG OH HX GI NQ DV SL RP SZ SF, in the rst horizontal line and in the second, third and fourth vertical columns of Fig. 10. At contacts 201 relay SC energizes magnet 240 which again shorts trouble alarm dash pot relay TA at contacts 243 and relay SC at contacts 208 again operates magnet |30 of scanning switch RSCI. When relay BP restores to terminate the pulse, relays SM, DA, TAB and SC restore and magnet |40 restores to step the wipers of the reading switch RDK to engage their rst bank contacts. Relay TAB in restoring opens the tabulator pulse to the distributor and relay SC in restoring restores magnets 240 and |30. Magnet 240 in restoring steps the wiper 244 to engage its second bank contact while the restoring of magnet |30 steps the wipers |3||35 of the iirst scanning switch to engage their second bank contacts which are cross connected through the distributing frame to the first live space computer indicators for flight |03.

These first ve indicators of ight number |03 are tested and read by the stepping of the reading switch RDK as previously described to cause the teleprinter to print the code letters, such as D, D, T, T, and O, in the second horizontal line and to the right of the numeral |03 shown in Fig. 10. When reading switch RDK again engagesr its tenth bank contact, another tab code is sent through the distributor to position the carriage so that the next code letter, such as T, may bey printed directly under the pair of code letters NQ (North Platte) as shown in Fig. the wiper 244 is advanced to its third position; and the wipers of scanning switch RSC are advanced to their third positions Where the third bank contacts are cross-connected through the distributing frame to the second set of ve indicators assigned to night |03. The polarity, high or 10W, code marking on these five indicators are now read by reading switch RDK in its odd position to selectively operate the coding relays PR, NR and RR in accordance with the available seats indicated respectively by the positions of each indicator. The coding relays transmitting the necessary coded pulses to the distributor to cause the printing of the corresponding code letters on the bulletin.

When the second ve indicators of flight |03 have been scanned and have caused the code letters to be printed another tab operation takes place as previously described to position the carriage so that the next code letter may be printed under letters SF of the first horizontal line and fourth vertical column. Wiper 244 has been stepped to its fourth bank contacts and the wipers of the first scanning switch have been stepped to engage` their fourth bank contacts which are connected through the distributing frame DF to the third set of indicators assigned to flight |03.

In this case, since flight |03 comprises only eleven sectors, or legs, and therefore only eleven indicators, only one indicator is included in the third set of indicators for flight |03. This last indicator is cross-connected to the fourth bank contact accessible to wiper |3| while the fourth bank contacts accessible to Wipers |32, |33, |34 and |35 are connected through the distributing frame DF to ground to operateskip relay SK as previously described.

When the code letter E is printed directly below SF (San Francisco) and relay SK has operated. switchRDK to its tenth position as previously described, another tab operation takes place to position. the carriage so as to print the code letters for flight |05. .The first scanning switch has beenoperated to engage its fifth set of bankcontacts and the wiper 244 has been advanced to engage its fifth bank contact. In the same manner as previously described, the indicators of flight |05 are successively scanned by the reading switch RDK to operate the code relays in accordance with the available seating capacity remaining for the respective legs of flight |35, as indicated by the wiper positions of the tens and units switches of each indicator.

4After the code letters have been printed in the fifth column and the wipers of switch RDK have been advanced to their tenth position, the next operation of pulse relay BP completes a circuit for operating the carriage return relay CR as follows: ground, contacts 222, 2|2, conductor |92, wiper |42 and its tenth bank contact, conductor |15, wiper 244 and its fifth bank contact, conductor |89., contacts |12, conductor |81 and relay CR tok battery. Carriage return relay at contacts 2|0 causes a carriage return pulse to be transmitted to the distributor to cause the teleprinter to perform a carriage return so that the carriage will be moved to a position preparatory to the printing of the code letters for flight |09 in the fourth horizontal line in the first vertical column. Flight It is from Denver (DV) to San Francisco (SF) and comprises three sectors, or legs, as indicated by the pairs of letters DV OG SZ SF in the third horizontal row of Fig. 10. Relay CR at contacts 233 again opens the circuit to relay DA before it can fully operate and at contacts 204 again operates relay VB. Relay VB at contacts 20| again shorts relay VA and maintains itself operated after relay CR releases. When the relay BP restores relay CR restores to remove the short from relay VA thereby permitting relay VA to operate in series with relay VB. Relay VA at contacts |13 closes a locking circuit for its upper winding which is effective on the next operation of relay BP and at contacts |12 prepares a circuit for line feed relay LS and step relay SC.

When relay BP again operates, relays CL and SM operate and line feed relay LS and step relay SC operate. The circuit for operating relays LS and SC at this time includes wiper 244 and its fifth bank contact and contacts |12 of relay VA. At contacts 200 line feed relay LS transmits a code pulse through the distributor for causing the bulletin to be positioned so that the first code letter for flight |09 will be printed directly below letters OG of the third horizontal line and to the right of numeral |09 in the fourth horizontal line in the rst vertical column of Fig. 10. Relay DA and magnet |40 also energize and relay SC also energizes magnets 240 and |30 as previously described. When relay BP restores relays LS, SC, SM and DA and magnet |40 restores to step wipers I4||43 to their first bank contacts. When relay SC' restores magnets 24o and |30 restore to step the wiper 2M toits sixth bank contact and the wipers |3|-l35 to their sixth bank contact. Wipers |3|, |32 and |33 have access to the three indicators assigned to ight |09 over their sixth bank contacts while the sixth bank contacts of wipers |34 and |35 are cross connected through the distributing frame to ground to cause the operation of skip relay SK as previously described. The setting of the three indicators for flight |39 are successively read in the manner previously described to control the coding relays to cause the teleprinter to print the code letters for flight |39 on the bulletin.

In the same manner as just described all of the indicators accessible over the wipers |3|-|35 of the first scanning switch RSCI are successively scanned to cause the printing of the code letters, corresponding to the available seats remaining in each sector of a flight, on the bulletin. When the last indicator accessible to switch RSCI has been read and the proper code printed on the bulletin the wipers I3||35 of the first scanning switch RSCI are stepped into engagement with their fiftieth bank contacts or to their normal positions. In normal position off-normal contacts |31 and |33 open while contacts |33 close. At contacts |38 the circuit to relay KP is opened and relay KP, being a slow to-release relay, maintains contacts |55 closed for a short interval. During this interval a circuit for energizing stepping magnet 250 of the date switch ROD is closed as follows: ground, off-normal contacts |39 and over a chain circuit including all forty-two of the scanning switches and their off-normal contacts, such as contacts |39', contacts |55, conductor |02, winding of magnet 250 to battery.

At contacts 252 magnet 250 completes a short circuit around the time relay TB. This short circuit is effective to restore the relay before it is fully operated if no circuit fault occurs in the previously described circuit operations. Relay TB is only fully operated if a failure occurs to ground the trouble alarm lead.

When relay KP restores this circuit is broken and magnet 250 restores to step the fifteen wipers of the date switch ROD to engage their second set of bank contacts. As is noted only one of these wipers I is effective at this time since the hand switch 29| is connected to only wiper I. The circuit is now prepared for the stepping magnet of the second scanning switch RSCZ as illustrated in Fig. 4.

After the last indicator accessible to the first scanning switch RSCI has been read and the code letter printed on the bulletin, the RDK and RSH switches are stepped to their tenth positions. The apparatus is now as shown in Figs. l and 2 with the exceptions that switch RSCZ is selected instead of switch RSCI and relays ST and PU are operated. When relay BP next operates relays CR, CL, SM and VB operate in a now obvious manner to cause the printer to perform a carriage return operation. Relay VA also operates when the carriage return relay CR restores at the end of the pulse. On the following pulse operation of relay BP relays LS, SC, DA, CL, SM, and magnets |40, 240 and the stepping magnet of the second scanning switch RSCZ operate and at the end of this pulse these relays and magnets are restored and the respective switches step their wipers to engage their first bank contacts, while the line feed relay LS has caused the printer to perform a line feed operation, all in a manner similar to that previously described. Relay KP is again operated when off-normal contacts (not shown) of switch RSCZ steps from normal as follows: ground contacts |39 of the first scanning switch RSCI, operated off-normal contacts (not shown) of the second scanning switch, corresponding to contacts |38, conductor |50 and relay KP to battery.

The apparatus is now set to scan the indicators accessible to the second scanning switch RSCZ and to print the code letters on the bulletin in accordance with the available seats as determined by the tens and units wipers of these indicators. The reading and printing of the bulletin for the indicators accessible to scanning switch RSC2 is similar to that previously described. When all the indicators accessible to the switch RSCZ have been read and switch RSC2 is advanced to its normal position the circuit to relay KP is interrupted by its off-normal contacts and before relay KP restores a ground pulse is transmitted through contacts |55 for operating the stepping magnet 250 of the date switch to step the date switch wiper I to engage its third bank contact where the third scanning switch RSC3 is controlled to take the readings of the space indicators accessible thereto in a manner similar to that previously described. The date switch ROD is stepped one step after each selected scanning switch has completed one revolution. Fig. 7 diagrammatically illustrates the respective bank contacts of the iirst level and their multipled connections to the designated scanning switches. It will be noted that the scanning switch RSCI is multipled to contacts I, I6, 32, 5|, 66 and 82 so that the indicators associated with scanning switch RSCI are read six times during a complete revolution of the date switch ROD. The scanning switches RSCI, RSCZ and RSC3 have access to the space indicators corresponding to the various nights for the current day of the week which is today, or Monday, as designated MOI, and each of these switches are operated six times during one revolution of the date switch ROD when the first wiper thereof is actuated by the hand switch 29 I. In a manner apparent from Fig. '1 the number of times the remaining scanning switches are operated from this level is illustrated. That is, the scanning switches RSC1, RSC8 and RSC9 for the following day of the week, or Tuesday, designated TUI, are likewise operated six times, while the scanning switches RSC22, RSC23 and RSCZII for the second Tuesday of the week, designated TU2, are only operated once in this level.

Fig. 8 designates all of the multiple connections to the scanning switches RSCI, RSCZ and RSC3 for all fourteen levels of the date switch. As will be noted, when the hand switch 29| has been moved to select level 2, corresponding to Tuesday, (TUI) after all nights for Monday have departed, the scanning switches RSCI, RSCZ and RSC3 are only multipled once in this level, since MOI now corresponds to a Monday two weeks from the just departed Monday nights. Fig. 9 is similar to Fig. 8 in that it shows all the Tuesdays TUI multipling of the scanning switches RSC1, RSCB and RSC9 in all fourteen levels. Fig. 6 shows a chart having fourteen vertical rows corresponding to the fourteen levels of the date switch ROD and the number of times the scanning switches for the respective days of the two week period are multipled in each level. As will be seen MOI is multipled six times in the first level, or the first vertical row, in horizontal rows I, 6, II, I1, 22 and 21 and only once in the second level, or the second vertical row, in horizontal line 3 I.

Referring now to Fig. 2 it will be noted that the 25th, 50th and '15th bank contacts are multipled in order to automatically step the wipers of the date switch ROD one additional step to their next adjacent bank contacts. For example, when wiper I5 engages its 25th bank contact the following circuit is completed for stepping magnet 250; ground, wiper I5, bank contact 25 and multiple connections, conductor 290, off-normal springs 253 of the date switch, interrupter springs 25| and winding of magnet 250 to battery. Magnet 250 energizes over this circuit and near the end of its armature stroke operates contacts 25| to interrupt its own circuit whereupon magnet 25o de-energizes to step the wipers to the next bank contact.

The apparatus continues to print on the bulletins until all of the scanning switches RSC accessible from the first level of the date switch ROD have been operated as previously described and when the last accessible scanning switch has been operated and restored to normal the date switch ROD operates its wipers to engage their hundredth bank contacts. When wiper I5 of the ROD switch engages its hundredth bank contact slow-to-release relay B is energized over a circuit as follows: ground, wiper I5, th bank contact, conductor 211 and winding of slow-torelease relay B to battery. Relay B at contacts 214 completes an obvious circuit for operating 

